Police have arrested the former head of Germany’s BND foreign intelligence agency, August Hanning, on suspicion of espionage.

The federal prosecutor’s office, announcing the development in a statement on Tuesday, said Mr Hanning was arrested at his home in Nordwalde near the western German city of Münster.

Mr Hanning is facing allegations bordering on espionage, disclosure of state secrets, attempted treason, and working as a secret service agent.

He is also accused of “aiding and abetting attempted treason and espionage against the state”.

“(Hanning is) in close contact with a representative of another foreign intelligence service, to whom he passed on political information, partially based on material provided by Manfred D., for several years,” the statement said.

DW’s chief political editor Michaela Küfner, who reported the development through the government press, described the case as Germany’s “biggest espionage scandal of the century unfolding in real time”.

Mr Hanning’s alleged accomplice, Hanni, as Manfred D. is known in Germany due to privacy laws, was also taken into custody in Bavaria. Both had worked together at Germany’s interior ministry until 2009.

According to the prosecutors’ office, the duo reportedly came up with their arrangement in 2010.

“The current findings suggest that, over the years, Manfred D. provided Hanning with approximately 2,000 documents, many of which contained classified information to be used exclusively by the Federal Intelligence Service for internal purposes,” the statement added.

The chairman of the German parliament’s intelligence oversight committee, Marc Henrichmann, noted that following the arrest, Germany “will not tolerate the betrayal of secrets”.

“Whoever allies themselves with the enemies of our liberal democracy will be found out,” Mr Henrichmann stated.

While the prosecutors confirmed ongoing searches of both suspects’ properties, the duo were expected to appear before an investigating judge on Tuesday (today) and Wednesday (tomorrow).